Free sulfhydryl groups in ripening fruits.
Tabachnik-Ma'ayan L., Fuchs Y.
Author Affiliation: Volcani Center, Bet Dagan, Israel.
Plant and Cell Physiology 23 : 1309-1314
Abstract : Ripening was accompanied by an increase in the content of sulphhydryl group (SH) in Angela and var. 599 tomatoes, Haden mango fruits, and Galia but not Ogen melons. In Valencia oranges (non climateric) the high SH levels did not change during development and maturation. The non-ripening tomato mutants nor and rin showed low constant SH levels during growth and senescence. Good ripening conditions such as high temperature (30 deg C) and ethylene treatment hastened the increase in SH in ripening tomatoes while slow ripening conditions such as low temperature (2 or 12 deg ) and low oxygen slowed the SH increase. Storage of red tomatoes at 30 deg increased SH content above that occurring at 2-20 deg . Ripening of green tomatoes was not affected by treating with SH compounds (reduced glutathione, cysteine), dithiothreitol or the SH-binding compound n-ethylmaleimide. The increase in SH therefore appears to accompany but not regulate ripening.